From 3a2d800ec17e718af81763fe0ab94c3bbfe8aa7d Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Tue, 31 May 2016 22:52:12 -0700
Subject: [PATCH] faster scrypt.

---
 lib/bcoin/scrypt.js | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/lib/bcoin/scrypt.js b/lib/bcoin/scrypt.js
index 1a29bed7..05c783c4 100644
--- a/lib/bcoin/scrypt.js
+++ b/lib/bcoin/scrypt.js
@@ -143,19 +143,19 @@ function blockmix_salsa8(B, Y, r) {
   var X = new Buffer(64);
   var i;
 
-  blkcpy(X, B.slice((2 * r - 1) * 64), 64);
+  blkcpy(X, B, 0, (2 * r - 1) * 64, 64);
 
   for (i = 0; i < 2 * r; i++) {
-    blkxor(X, B.slice(i * 64), 64);
+    blkxor(X, B, 0, i * 64, 64);
     salsa20_8(X);
-    blkcpy(Y.slice(i * 64), X, 64);
+    blkcpy(Y, X, i * 64, 0, 64);
   }
 
   for (i = 0; i < r; i++)
-    blkcpy(B.slice(i * 64), Y.slice((i * 2) * 64), 64);
+    blkcpy(B, Y, i * 64, (i * 2) * 64, 64);
 
   for (i = 0; i < r; i++)
-    blkcpy(B.slice((i + r) * 64), Y.slice((i * 2 + 1) * 64), 64);
+    blkcpy(B, Y, (i + r) * 64, (i * 2 + 1) * 64, 64);
 }
 
 function integerify(B, r) {
@@ -168,29 +168,29 @@ function smix(B, r, N, V, XY) {
   var i;
   var j;
 
-  blkcpy(X, B, 128 * r);
+  blkcpy(X, B, 0, 0, 128 * r);
 
   for (i = 0; i < N; i++) {
-    blkcpy(V.slice(i * (128 * r)), X, 128 * r);
+    blkcpy(V, X, i * (128 * r), 0, 128 * r);
     blockmix_salsa8(X, Y, r);
   }
 
   for (i = 0; i < N; i++) {
     j = integerify(X, r) & (N - 1);
-    blkxor(X, V.slice(j * (128 * r)), 128 * r);
+    blkxor(X, V, 0, j * (128 * r), 128 * r);
     blockmix_salsa8(X, Y, r);
   }
 
-  blkcpy(B, X, 128 * r);
+  blkcpy(B, X, 0, 0, 128 * r);
 }
 
-function blkcpy(dest, src, len) {
-  src.copy(dest, 0, 0, len);
+function blkcpy(dest, src, s1, s2, len) {
+  src.copy(dest, s1, s2, s2 + len);
 }
 
-function blkxor(dest, src, len) {
+function blkxor(dest, src, s1, s2, len) {
   for (var i = 0; i < len; i++)
-    dest[i] ^= src[i];
+    dest[s1 + i] ^= src[s2 + i];
 }
 
 /*